We live in the age of artisanal everything, from chocolate and coffee, to, you guessed it, water.
At Mexico City's Casa del Agua, staff produce and bottle "local water" on-site. The bottles—designed artisanally, of course—are charming souvenirs that you can use over and over again (with your own, less expensive water) once you're home.
Be sure to go to the second level of the shop to see the filtration process, and to the terrace level to see where the water is captured.